The present invention related generally to door locking bolt mechanisms, and manually operable means for the actuation of such bolts.
When such mechanisms are installed for utilization on aircraft doors, such as a cabin door mounted in the skin structure of the main passenger cabin, the mechanisms must comply with Federal Air Regulations 25 which have been interpreted as requiring a one motion inside handle to release the door bolt or bolts.
In one early prior know concept, it was proposed to provide an interconnected bolt actuating inside handle and an outside T-shaped handle normally having a flush mounted latching position, but which was arranged to pop out into a released position upon actuation of a trip release means associated with the inside operating handle. This arrangement was considered to be a two motion operation of the inside handle, and therefore did not conform with the commonly understood interpretation of the Federal Air Regulations.
Subsequently, another concept was conceived and developed to meet the Federal Air Regulations requirements, such concept being disclosed in the Adams Rite Manufacturing Co. Drawing No. 2330, and having been known publicly since 1964. Briefly, the disclosed structure provides a T-shaped inside handle which is secured to one end of a rotatably mounted main shaft in the door structure, this shaft being connected with an actuating crank that is operatively connected with the door bolts. An outside door handle comprises a single hand-grip lever that is pivoted at one end to the outer end of the main shaft for swinging movements between a retracted substantially flush seated position in a recess of an outside escutcheon plate so as to releasably latch the crank in a bolted position. A spring at the pivoted end of the handle normally urges the hand-grip lever into retracted position. Adjacent its pivoted end, the lever is provided with a roller which is adapted, upon rotation of the main shaft by the inside handle, to ride up an arcuate cam ramp and thus move the lever out of its latching recess as continued rotation of the main shaft moves the crank to a bolt unlocked position. The single outside hand-grip lever may also be utilized to actuate the crank and move it to a bolt unlocked position. For this operation, a finger may be inserted under the outer end of the lever, and by exerting a pulling force move the lever to a tilted unlatched extended position and then rotated to actuate the crank.
The present invention constitutes an improvement over the concept disclosed in the above noted drawing, and embodies a number of desirable features which contribute to the ease of operation and make the mechanism more dependable during long periods of operative use. Such features include:
A. Provision of an outside T-handle having oppositely extending hand-grip portions which enable the use of two hands for the application of greater and equilized operating torque forces. PA1 B. The inclusion of a unique actuating and equalizing interconnection means between the outside hand-grip portions, whereby tilting movements of one of the hand-grip portions will result in a similar movement of the other hand-grip portion. PA1 C. The provision of coacting seating V-surfaces at the outer ends of the hand-grip portions of the outside handle, which guide and assist in the movements of the hand-grip portions into and out of their retracted positions. PA1 D. An improved over-center spring arrangement, for urging the bolt actuating crank towards limit positions corresponding to the bolted and unbolted positions of the door bolts. PA1 E. An improved camming means for moving the pivoted hand-grip portions of the outer handle into tilted extended positions in response to rotation of the inner handle.